This invention relates to the antibiotic trovafloxacin having the formula ##STR4## and its pharmaceutically acceptable salts and prodrugs (hereafter "the active compounds"). More particularly, it relates to a process and compositions useful in the the preparation of compounds of the formula ##STR5## wherein R.sup.1, m, o and p are as described below. The compounds of formula III are intermediates in the preparation of the compound of formula I and the pharmaceutically acceptable salts and prodrugs thereof. The antibacterial activity of the aforementioned antibiotic is described in U.S. Pat. No. 5,164,402 (the '402 patent) and U.S. Pat. No. 5,229,396 (the 396' patent) issued Nov. 17, 1992 and Jul. 20, 1993, respectively, the disclosures of which are incorporated herein, by reference, in their entirety. The foregoing patents are assigned in common with the present application.
U.S. Pat. No. 5,256,791 (the '791 patent), issued Oct. 26, 1993, describes a process, for preparing a compound of formula III by adding a base to a solution of a compound of the formula II, described below, and a nitrohalomethane, described below, in an inert, non-aqueous solvent wherein the base consists of 1,8-diazabyclo-[5.4.0]undec-7-ene (DBU) and U.S. patent application Ser. No. 08/181,942 (the '942 application), filed Jan. 18, 1994, describes the use of dimethyltetrahydropyrimidine (DMTHP) as the base in a similar process. The foregoing references are assigned in common with the present application and are incorporated herein, in their entirety, by reference.
The methods by which the compounds of formula III may be converted into the compound of formula I are set forth in detail in the aforementioned '791 patent.